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O: Fachverband Oberflächenphysik

O 83: Poster Session VI: Poster to Mini-Symposium: Infrared nano-optics IV

O 83.1: Poster

Mittwoch, 3. März 2021, 13:30–15:30, P

Dipole model for far-field thermal emission of a nanoparticle above a planar substrate — •Florian Herz and Svend-Age Biehs — Institut für Physik, Carl von Ossietzky Universität, D-26111 Oldenburg, Germany

I will present our latest efforts in developing a dipole model describing the thermal far-field radiation of a nanoparticle close to a substrate. The nanoparticle serves as a first approximation for the cantilever tip usually used in infrared near-field thermal imaging experiments [1-3].

We generalized existing approaches by including the possibility to have different temperatures for substrate, nanoparticle, and background to cover setups like the thermal radiation scanning tunnelling microscope (TRSTM) [1], the thermal infrared near-field spectroscopy (TINS) [2], and the scanning noise microscope (SNoiM) [3]. Apart from the induced electric dipole moment, we also considered eddy currents being particularly important for metallic particles. Furthermore, instead of neglecting divergent terms of the Green's function appearing in the dipole model, we carry out a renormalization procedure.

I will explain how we methodically incorporated these generalizations and discuss how they affect the numerical simulations. Additionally, I will discuss the impact of parameters like particle size and emission angle as well as the distance dependence for all four combinations of the materials gold and SiC for nanoparticle and substrate.

1 Y. De Wilde et al., Nature 444, 740 (2006)

2 A. C. Jones and M. B. Raschke, Nano. Lett. 12, 1475 (2012)

3 Q. Weng et al., Science 360, 775 (2018)